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cognos79
Posting Yak Master
241 Posts |
 Posted - 2006-12-27 : 10:31:43
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| when i create a new database using the wizard they are created automatically. why do we need them? what is the purpose |
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harsh_athalye
Master Smack Fu Yak Hacker
5581 Posts |
Posted - 2006-12-27 : 10:39:46
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From BOL: quote:
.mdf - Primary data file .ldf - Transaction log fileThe primary file contains the startup information for the database. The primary file is also used to store data. Every database has one primary file.Transaction log files hold the log information used to recover the database. There must be at least one transaction log file for each database, although there may be more than one.
Harsh AthalyeIndia."The IMPOSSIBLE is often UNTRIED" |
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Michael Valentine Jones
Yak DBA Kernel (pronounced Colonel)
7020 Posts |
Posted - 2006-12-27 : 10:42:06
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quote:
Originally posted by cognos79
when i create a new database using the wizard they are created automatically. why do we need them? what is the purpose
MDF files hold the database objects. LDF files hold the database trasactions.CODO ERGO SUM |
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cognos79
Posting Yak Master
241 Posts |
Posted - 2006-12-27 : 10:43:11
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| harsh...does it mean that I can restore the database from one of these files if the database is broken??? also can i view the contents of these .mdf and .ldf files??? |
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harsh_athalye
Master Smack Fu Yak Hacker
5581 Posts |
Posted - 2006-12-27 : 10:53:28
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| Yes, there are some third party tools available which will allow you to restore database from log file, but you should not rely on using such tools. Maintaining regular database backups is a good strategy.Also, you can't directly view the contents of any of these files.Harsh AthalyeIndia."The IMPOSSIBLE is often UNTRIED" |
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cognos79
Posting Yak Master
241 Posts |
Posted - 2006-12-27 : 11:09:58
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| Thanks a lot guys... |
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maheshcr
Starting Member
1 Post |
Posted - 2007-01-02 : 20:12:19
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| What are the tools available to restore database from just the .LDF file?Thanks for any help,Mahesh |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2007-01-02 : 20:19:31
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| there are NO tools that can gurantee to restore from log file alone. depends on recovery model among other factors. as Harsh said, maintain regular backups. as though your job depended on it...because it probably does... :) |
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Kristen
Test
22859 Posts |
Posted - 2007-01-03 : 03:52:27
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| "What are the tools available to restore database from just the .LDF file?"None that I know of. But there are tools that will "read" the LDF file, and from that transactions that occurred during a period of time can be "selectively" re-runWith the database in Full recovery model it is better to just rely on the backups which allow you to:Restore from last FULL backup (e.g. last night, or last-Sunday etc.)Restore more recent DIFF backup (optional)Restore ALL subsequent TRANSACTION backups up to the time the restore is required - it is possible to restore the last Trans. backup to a specific TIME - rather than having to restore the whole file.Kristen |
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.mdf and .ldf files